For over a decade, graphene has received a lot of attention as a next-generation material, opening new opportunities for multipurpose applications, from wet-chemistry to future electronic devices. Although a variety of established methods for the preparation of graphene and/or graphene-like materials exist, each method has its strengths and weaknesses for commercialization. New prospective methods must be simple, inexpensive, and eco-friendly processes, allowing for mass production with high quality. This can be realized by edge-selective functionalization of graphene nanoplatelets (GnPs) using Friedel–Crafts acylation and mechanochemical reactions. Unlike graphene oxide/reduced graphene oxide, the preparation of edge-selectively functionalized GnPs (EFGnPs) does not include hazardous chemicals. In addition, a variety of functional groups and/or heteroatoms can be selectively introduced at the edges, allowing the tunability of the GnP properties for specific application purposes. Furthermore, the minimal defects in the basal area together with the multifunctionalities of EFGnPs enable the achievement of outstanding performances in various applications, such as in polymer composites, flame retardants, and energy conversion and storage systems. Since this newly-developed method of edge functionalization allows the control of the GnPs characteristics, the resultant EFGnPs have unlimited potential in various applications and they will, indeed, be recognized as next-generation materials soon.